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# Average Speed Formula

The average speed of an object tells you the (average) rate at which it covers distance. Average speed is a measure of the distance traveled in a given period of time; it is sometimes referred to as the distance per time ratio. If a car's average speed is 65 miles per hour, this means that the car's position will change (on the average) by 65 miles each hour. Average speed is a rate. In kinematics, a rate is always a quantity divided by the time taken to get that quantity (the elapsed time). Since average speed is the rate position changes, average speed = distance traveled/time taken.
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Average Speed is given by the formula:

Average speed formula helps you to calculate the average speed for the set of different distances d1, d2..... dn if their corresponding different time intervals t1, t2,....tn are given.

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## Average Speed Problems

Below are solved examples for average speed:

### Solved Examples

Question 1: A car travels a distance of 30 miles for 2 hrs and 45 miles for next 3 hrs. Calculate its average speed.
Solution:

Average Speed is given by SAvg = $\frac{Total\ Distance\ Covered}{Total\ time\ taken}$
Total distance traveled Dtotal = 30 miles + 45 miles = 75 miles.
Total time taken t = 2 hr + 3 hr = 5 hr.
SAvg = $\frac{Total\ Distance\ Covered}{Total\ time\ taken}$
= $\frac{75 miles}{5 hr}$
= 15 miles/hr.

Question 2: Laura is practising for a running race. For 1st $\frac{1}{2}$ hour he runs 0.25 miles and for the next $\frac{1}{2}$ hour she runs for 0.2 miles. Calculate the average speed?
Solution:

Average Speed is given by SAvg = $\frac{Total\ Distance\ Covered}{Total\ time\ taken}$
Total distance traveled DTotal = 0.25 miles + 0.20 miles = 0.45 miles.
Total time taken t = $\frac{1}{2}$ hr + $\frac{1}{2}$ hr = 1 hr
SAvg = $\frac{Total\ Distance\ Covered}{Total\ time\ taken}$
= $\frac{0.45 miles}{1 hr}$
= 0.45 miles/hr.

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